1. Field of the Invention
This invention relates to wheelchair ramps, and, more particularly, to a powered wheelchair ramp that can be placed on a surface and that is adapted to be pivoted at one end to engage with a step to facilitate wheelchair passage over the step, or used to facilitate wheelchair boarding of a means of transportation such as a bus, streetcar, railway car or commuter rail car.
2. Description of the Prior Art
In recent years there has been a greater recognition that access to public facilities and transit systems by those confined to wheelchairs is rendered difficult by the presence of curbs, steps, and the like. As a result, various regulations have been adopted to require that ramps be provided at curbs at intersections, that ramps be provided for access to public buildings, that buses be equipped with lifts, and that transit authorities purchase rail cars with access equipment, and the like, to facilitate such access.
In order to facilitate movement by those confined to wheelchairs, various devices have been developed. For example, in U.S. Pat. No. 3,936,898, that issued Feb. 10, 1976, there is disclosed a portable ramp for wheelchairs in the form of a pair of rectangular plates that are hingedly connected along a pair of longer edges. The ramp includes a pair of tubular legs adjacent to the corners of one side to permit the ramp to be placed in an inclined position, to thereby permit a wheelchair to travel from a first level to a second level by means of the ramp, which is positioned adjacent to a step.
A power operated ramp is disclosed in U.S. Pat. No. 4,084,713, that issued Apr. 18, 1978, the ramp being secured to a vehicle and capable of folding for easy storage. One end of the ramp is hingedly secured to the floor of the vehicle, and the ramp unfolds outwardly so that the free end contacts the ground. The ramp defines a flat, inclined surface to permit the wheelchair and occupant to enter and leave the vehicle without the need for traversing steps.
In addition to the provision of wheelchair ramps, the prior art also discloses movable ramps used in connection with loading and unloading facilities for trucks. Examples of such patents are U.S. Pat. Nos. 3,500,486, that issued on Mar. 17, 1970; 3,882,563 that issued on May 13, 1975; and 3,894,515, that issued on July 15, 1975. A similar arrangement is illustrated and described in U.S. Pat. No. 3,628,209, that issued on Dec. 21, 1971, and that shows a device for connecting with an access surface several superposed levels of a structure.
Although the prior art discloses various types of ramp constructions for various uses, the disclosed ramps that are power operated are somewhat complicated and cumbersome, and the portable ramps are inconvenient to use. Therefore, there is a need for a simplified ramp construction that is permanently placed adjacent to a step or transit vehicle boarding site and that can be power operated to cause the ramp to extend between the upper and lower surfaces and thereby permit unimpeded travel by one confined to a wheelchair. It is therefore an object of the present invention to provide such an arrangement.